<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>设置扇形和圆形</title>
    <style type="text/css">
        div{
            background: orange;
            margin: 20px;
        }
        div:nth-of-type(1){
            width: 50px;
            height: 50px;
            border-radius: 50px 0 0 0; /*左上*/
        }
        div:nth-of-type(2){
            width: 50px;
            height: 50px;
            border-radius: 0 50px 0 0; /*右上*/
        }
        div:nth-of-type(3){
            width: 50px;
            height: 50px;
            border-radius: 0 0 50px 0; /*右下*/
        }
        div:nth-of-type(4){
            width: 50px;
            height: 50px;
            border-radius: 0 0 0 50px; /*左下*/
        }
        div:nth-of-type(5){
            width: 50px;
            height: 50px;
            border-radius: 50px; /*设置所有 圆形*/
        }
    </style>
</head>
<body>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
</body>
</html>